Protecting integrated circuits in ever decreasing packages has become increasingly difficult and costly. Integrated circuits or semiconductors usually are encapsulated in a package prior to installation into an electronic system. Device, die or chip packages perform several key functions such as, connecting integrated circuits to an electronic system at a next level of integration or hierarchy, physical protection from further handing and additional manufacturing processes, environmental protection including environments within multiple levels of electronic systems and heat dissipation from the integrated circuits and other components. These functions present chipmakers with a number of design and manufacturing challenges that must also be balanced with factors such as cost and pricing.
Flip-chip packaging is one type of electronic chip packaging technology, and has been in existence for many years. Flip-chip packaging has progressed to include a wide variety of materials and methods for bumping and attaching devices. Although the technology has progressed, challenges still exist in solving problems with manufacturing yield, device reliability, higher frequency applications, tighter space requirements, reduced costs, and general device performance. Many of the challenges to solving these continuing problems can be attributed to some key packaging issues including bump collapse level, bump spread distance and paddle damage such as paddle delamination.
A bump is placed onto the integrated circuit die contact, heated, and cooled to reflow the alloy to form a bump and to bond the bump to the integrated circuit die. The integrated circuit die is then assembled with the package so that the bump rests upon the corresponding package contact. The assembly is heated and cooled to bond the bump to the package. This attaches the integrated circuit die to the package and electrically connects the contacts for conducting electrical signals, with the integrated circuit die and the package spaced apart by the bump. During reflow, the bump tends to collapse under the weight of the integrated circuit die, creating a collapsed configuration that tends to concentrate stresses at the solder bonds and reduces the spacing thereby restricting access for encapsulation, cleaning or other post-connection operations.
Integrated circuit packages also provide electrical interconnection of integrated circuits to an electronic system at the next level of integration or hierarchy. A leadframe is one common means of electrical interconnection. The leadframe is formed from electrically conductive material, which is formed into leads. The lead ends are electrically connected to the integrated circuit die and the next level electronic system including external circuitry such as a printed circuit board. The leadframe also often include a die attach paddle to mount the integrated circuit die. The large surface area, exposed edges and narrow component spacing of the die attach paddle are often susceptible to manufacturing problems including damage during encapsulation of the integrated circuit package.
Integrated circuits are used in many portable electronic products, such as cell phones, portable computers, voice recorders, etc. as well as in many larger electronic systems, such as cars, planes, industrial control systems, etc. Across virtually all applications, there continues to be demand for reducing the size and increasing performance of the devices. The intense demand is no more visible than in portable electronics that have become so ubiquitous. As the demand for smaller electronic devices grows, manufacturers are seeking ways to reduce the size of the packaged integrated circuits. To meet these needs, packaging technologies are increasingly using smaller area designs with smaller features.
Thus, a need still remains for an integrated circuit package system to provide improved reliability and manufacturing yield with smaller features in smaller area. In view of the increasing demand for improved density of integrated circuits and particularly portable electronic products, it is increasingly critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.